ios - AVAudioPlayer 问题(如果设备被锁定，音乐文件无法在后台模式下播放)

Question

如果设备未锁定，则音乐将在后台播放。我已将代码粘贴到 .Plist 文件中，这是我使用的代码

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:saveFileName];
    NSURL *url1 = [[NSURL alloc] initFileURLWithPath: path];
    appdelegate.sharedplayer=[[AVAudioPlayer alloc] initWithContentsOfURL:url1 error:NULL];
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
    [[AVAudioSession sharedInstance] setActive: YES error: nil];
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

    [appdelegate.sharedplayer setVolume:appdelegate.volumeDelegate];

    [appdelegate.sharedplayer play];

Answer 1

当设备被密码锁定时，Apple iOS 会限制数据访问。所以你将 NSDocumetDirectory 转换为歌曲的 NSData。并分配它工作的 AVAudioPlayer。

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:saveFileName];
NSURL *url1 = [[NSURL alloc] initFileURLWithPath: path];
NSData *data=[[NSData alloc]initWithContentsOfURL:url1];
appdelegate.sharedplayer=[[AVAudioPlayer alloc] initWithData:data error:nil];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
[[AVAudioSession sharedInstance] setActive: YES error: nil];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[appdelegate.sharedplayer setVolume:appdelegate.volumeDelegate];
[appdelegate.sharedplayer play];